M20B23 motor and Getrag 5 speed from a 1985 E30

[black bmw 318]

hi guys

i can get a M20B23 1985 motor very cheap.
i was thinking about using it as a starting block to build upon.

what would you recommend? should i put on a late model i head?
what else will i then need to change?
i assume crank, pistons? i ecu and injectors?

or would i be better off looking for a complete late model i engine and just impoving on that?

any help appreciated

cheers

[AdamF 88iS]

Use the head you have, get E rods and pistons, and a TD or E crank.

[bkelsey86]

Use the head you have, get E rods and pistons, and a TD or E crank.

werd 8)

[black bmw 318]

confused now...

i dont have an "i" head, but i can get a cheap 85 M20B23 motor.

should i put an "i" head on it?
what else would i need, pistons?

[nando]

they are saying to use your B23 head on the equivalent of an eta block.

[AdamF 88iS]

The b23 head is special. Use that with a b27 bottom end.

[Switch]

question...... *rasies hand steadily*

the 2.5 head has larger valves ect ect. then the 2.3 head (right?)

so wouldn;t the 2.5 head be a better canidate for a stroker....


whats so special about the 2.3 head?
i am in same position, i can also get a b23 head for cheap..

[decay]

question...... *rasies hand steadily*

the 2.5 head has larger valves ect ect. then the 2.3 head (right?)

so wouldn;t the 2.5 head be a better canidate for a stroker....


whats so special about the 2.3 head?
i am in same position, i can also get a b23 head for cheap..

search on keyword "731".

also, i'll be upping my valves to i-sized before mine goes in on top of an eta block.

[nando]

question...... *rasies hand steadily*

the 2.5 head has larger valves ect ect. then the 2.3 head (right?)

so wouldn;t the 2.5 head be a better canidate for a stroker....


whats so special about the 2.3 head?
i am in same position, i can also get a b23 head for cheap..

sure but you can't just bolt it onto an e block. it would be easier to get a cam and oversized valves for the 2.3 head.

[Switch]

searched for 731... so the euro 323 head has I sized valves..... and a higher lift on the cam.. (which would give it.. more high end??)

thats kinda cool... so its basically an 2.5 head with a stock higher cam...

so.. why won;t it just bolt onto an eta? (or super eta?) low compression issues?

[decay]

thats kinda cool... so its basically an 2.5 head with a stock higher cam...

it would be more correct to say it's an eta head with i port passages. valves are the same as an eta, but intake manifold gaskets are the same as an i.

so.. why won;t it just bolt onto an eta? (or super eta?) low compression issues?

it will bolt up to an eta, super-eta or i blocks are what it's not compatible with.

compression ratio of the 731/eta combo has been reported here at ~9.8:1.

[Switch]

hmm, so basically mixing the two would give you the I head + eta block w/ higher compression..... grr. i guess the thing thats confusing me is.. why chose this method over i + eta w/ custom pstons (super eta)


what kind of power can one expect with 2.3 head plus eta bottom....?

sry if i am asking alot of questions...

[nando]

why chose this method over i + eta w/ custom pstons (super eta)

because custom pistons are around $800+ vs just bolting the 323 head onto the e block.

of course getting a 323 head is not easy so most people go custom..

[Switch]

hmm... and power difference between 731 head to custom pistons ect....


bascially..


would 731 head and eta bottom give e more power. low and high then a stock 2.5.... :)

[decay]

would 731 head and eta bottom give e more power. low and high then a stock 2.5.... :)

displacement goes from 2494cc to 2692cc

compression ratio goes from 8.8:1 to 9.8:1

that should tell you all you need to know.

i found my 731 head after about a month of searching. they're out there, you just have to be patient/vigilant and have the money ready to throw at one when it pops up.